CT Only: Supplement 7 Express Boat Tender

[Terquem]

Urggggh

I was sort of suggesting a new short adventure with my son and one of his friends and got back to looking at the tender design above, and it is driving me crazy. So many questions bother me about this

Why build a small ship to do maintenance on other small ships, and then waste all the space you have available to carry spares, or raw materials on a huge bay that accepts only a small number of other smaller ships?

Why not have external couplings, and several ten ton "pods" with locks for letting workers move in and around the ships under repair?

How much machinery is required to evacuate that huge bay of atmosphere (pump it into tanks) and then pump it back in each time you want to move a type "S" in or out?

Then I thought about those maintenance pods some more, and came up with an idea for a short scenario where the tender (redesigned) is boarded while a small tech crew is outside the ship in one of those pods (a party of three or maybe four Player characters) and they have to sneak back into the tender and overcome the pirates

 

[GypsyComet]

Why not have external couplings, and several ten ton "pods" with locks for letting workers move in and around the ships under repair?

That was an idea that was just coming to them by then. The idea of a ship that changed total displacement and performance only saw two examples in CT: The Gazelle CE, and the "Jump Ship" external cargo carrier from Fighting Ships. Easily used external grapples for this purpose were still two editions away. That's not to say you couldn't use them in CT; there is no mechanical incompatibility, and ship components are likely the most common bits of Traveller to jump editions.

 

[Terquem]

Those are good points, but I'm actually not even considering the Jump capabilities of the tender when it is servicing other ships (and I'll probably rework the design so that the tender can still Jump, with no more than 2 "coupled" 100 ton ships).

I'm seeing the role of the Tender differently than what I think the original designers had in mind.

I mean, for a while I was close to a Sub Tender in the US Navy (many centuries ago it seems). The Tender's function, its role, did not include moving from one location to another location while submarines were literally attached to it.

Do you get what I mean?

 

[snrdg082102]

Hello [FONT=arial,helvetica]Terquem,

My apologies if this information has already been supplied, gremlins have been messing with my access to the forum.

Supplement 7 Traders and Gunboats 1980 8th printing pp. 11, 14, & 15

Serve two purposes:
1. They tend express boats, recovering them when they arrive, refueling them, repairing minor problems, and then sending them on their way.

2. They serve as a relay station between the planetary surface based message center and the express boat itself. Messages are forwarded to the tender for transmittal to the x-boat just before it leaves for the next star system.

Other information
1. Express boat tenders are encountered anywhere that x-boats may be expected. High population, high technology systems will probably have several tenders operating in order to handle the flow of information.

2. Express boat tenders are jump capable, and each may carry up to four x-boats in its cavernous ship bay. As a result, the tenders can be found be found in fringe or off-route systems ferrying extra x-boats to areas that need them.

3. They also undertake recovery missions to pick up damaged x-boats or boats which have miss jumped to off-route system.

There have been discussions that the boat bay as built probably does not have the capacity to carry four x-boats.

However, carrying one or two in the boat bay does not change the tenders jump capability that carrying craft externally does. The Gazelle is a 300 d-ton with two 50 d-ton drop tanks. With the tanks retained the jump rating is 4 parses, dropping them allows a jump of 5 parsecs, without them, IIRC, the range is 2 parsecs.

Having the bay allows the tender's crew to work on an X-boat or IIRC a Type S Scout in a pressurized environment.

Of course I may be OTL on the subject.
[/FONT]

 

[Travellerspud]

space-wise there can only really be 2 Xboats inside....at least if one goes by the dimensions in book 7

however I always assumed there was some sort of "docking arms" that could extend to allow 2 more X-boats to be ferried (for the total of 4)

 

[Timerover51]

Those are good points, but I'm actually not even considering the Jump capabilities of the tender when it is servicing other ships (and I'll probably rework the design so that the tender can still Jump, with no more than 2 "coupled" 100 ton ships).

I'm seeing the role of the Tender differently than what I think the original designers had in mind.

I mean, for a while I was close to a Sub Tender in the US Navy (many centuries ago it seems). The Tender's function, its role, did not include moving from one location to another location while submarines were literally attached to it.

Do you get what I mean?

My oldest brother was assigned to a sub tender in San Diego back in the late 1960s, and the standard joke about the ship was that it could not move for the massive bank of coffee grounds under it. Once a sub tender got to its assigned port, it did not move a whole lot.

 

[GypsyComet]

The Tender's function, its role, did not include moving from one location to another location while submarines were literally attached to it.

The X-Boat Tender has to, though, at least with M-Drives, and may need to haul an inoperative XBoat to a port. Tenders have to move because the standard CT XBoat has no M-Drive. They pop out of Jump and call for pickup. The Tender goes to them, and may need to do so for more than one at a time. Some systems will have multiple Tenders, but not all, and even that doesn't mean they'll always be able to operate one-on-one.

Modern Sub Tenders are going to have parallels among SDB Tenders, since the SDB comes to them, but XBoats don't have that option as presented.

Of course, if you are re-designing the XBoat to have MDrive, that's another matter.

 

[snrdg082102]

Evening Travellerspud,

space-wise there can only really be 2 Xboats inside....at least if one goes by the dimensions in book 7

however I always assumed there was some sort of "docking arms" that could extend to allow 2 more X-boats to be ferried (for the total of 4)

About two years ago I made an attempt to take the Supplement 7 designs that were made using CT Book 2 1st edition with the CT Book 5 HG2e and TCS rules. I posted my findings here on the forum. One of the findings agrees that the boat bay could not physically fit four x-boats even though in theory there is enough volume to fit them. Unfortunately, I've given up my little project since I was not successful in convincing the forum members of recommendations to bring them up to CT Book 2 HG2e design rules.

The details for the tender clearly state that the tender's boat bay is supposed to carry four x-boats. The bay's volume of 600 d-tons can fit four 100 d-ton x-boats. Unfortunately, the dimensions of the bay will not hold four approximately 22 meter long x-boats.

The deck plans do show a refueling arm on the hulls exterior. However, carrying two x-boats externally increases the tenders volume which reduces the ship's jump and acceleration ratings.

 

[Terquem]

If you go to the page before this one you can see my 1700dt redesign of the Tender I will use in my next adventure.

I noticed a typo in the description, where the fuel tonnage is described once as 200dt, and then in another place as 250dt - I am going to go back over the design this weekend and see where I made the mistake. Our game is supposed to be played starting June 11th and might run over three nights (A friend of my son who moved away to Texas for his college will be in town that week, so I'm hoping to have everything ready by then)

 

[aramis]

space-wise there can only really be 2 Xboats inside....at least if one goes by the dimensions in book 7

however I always assumed there was some sort of "docking arms" that could extend to allow 2 more X-boats to be ferried (for the total of 4)

You can actually get 3 in. I did the vis in sketchup. Expand it just a couple meters vertically, and you can get 4 in. And still shut the doors. Note that the axes of the XB's are not parallel to each other nor the ship's... Nifty thing those conic things...

 

[Hyphen]

Here's magmagmag's version:

https://it.pinterest.com/pin/772156298582235949/

In a different scene, he has 2 boats inside (nose to tail) and one still out, but with room for 4...

I thin Jesse DeGraff could only fit in two:
https://members.tip.net.au/~davidjw/libdata/pictures/libdata/xboatend.jpg

And I'm sure I've seen (but can't now find) a pic showing how four can be made to fit.

 

[Hyphen]

This is from an earlier thread on the same topic:

 

[snrdg082102]

Hello Hypen,

This is from an earlier thread on the same topic:

The Express Boat Tender details on CT Supplement 7 Traders and Gunboats 1980 8th printing p. 11 Express Boat Tender (Type XT) first paragraph: The major part of the ship (600 tons) is taken up by a cavernous ship bay.

Interior Details p. 11: The most striking interior detail for the express boat tender is the ship bay. It measures 40 m x 28.5 m x 12 m.

Calculating the ship bay volume from the dimensions 40 m x 28.5 m x 12 m I get 13,680 m^3 or rounded to 977 d-tons. This is 377 d-tons more than the cited 600 d-tons.

The deck plan on p. 12 for the ship has the following information
40 meter ceiling
Maximum Capacity: 28.5 meters
Width: 12 meters Height: (24 meters if door remains open), 40 meter height.

which supports the text dimensions on p. 11. Unfortunately the numbers do not match the 600 d-ton volume.

600 d-tons = 8,400 m^3 = 40 m x 12 m x ? m
(8,400 m^3)/(40 m x 12 m) = ? m
8,400 m^3 / 480 = 17.5 m without taking into account the two lift shafts and the observation platform.

The number for the bay that matches the 600 d-ton of 17.5 m is 11 m shorter than the 28.5 m.

The link provided appears to be answer to my attempt three years ago to help Donald McKinney with verifying the CT designs in his Consolidated CT Errata. Back then I had not actually, as far as I can remember, verified the dimensions for the ship bay as I did above. Now I'm once again not sure if the express boat tender can actually fit four express boats.

Of course I am probably out in a field somewhere anyway.

 

[mike wightman]

Your error is not taking into account the curve of one of the dimensions...

you are calculating it as a box, which it isn't.

 

[snrdg082102]

Hello Might Wightman,

Your error is not taking into account the curve of one of the dimensions...

you are calculating it as a box, which it isn't.

You are correct I have screwed up. The ship bay appears to be a combination of a cylinder and a rectangle.

For the rectangle I am sure that from the bay access door to the overhead is 12 m and from the cargo bay bulkhead to the fuel tank bulkhead is 40 m. Counting the squares I get 14 and if the scale is 1.5 m per square the dimension is 21 m. the volume of a 40 m x 12 m x 21 m = 10,090 m^3 = 720 d-tons. Which exceeds the bays volume by 120 d-tons.

Looking at one the curved sections as a half cylinder the one dimension I am sure of is 40 m. On the deck plans I count three full squares which if the scale is 1.5 m is 4.5 m for half the cylinder. I'm guessing that the bits of squares shown represent 0.5 m bring the total to 5 m Putting the two curved sections together the cylinder appears have a 10 m. The volume of the cylinder is approximately PI x r^2 x H = PI x 5^2 x 40 = 3141.5927 m^3 = 224.3995 d-tons = 224 d-tons round to 224 d-tons

600 d-tons - 224 d-tons = 376 d-tons x 14 = 5263 m^3

5263 m^3/(40 x 12) = 5263/480 =10.9667 = 11 m

This is approximately 11 m + 5 m + 5 m = 16 + 5 = 21 m at the widest point.

If the 28.5 m is the widest point and the two curved sections provide 10 m then the area outside the curves is 18.5 m. 40 x 12 x 18.5 = 480 x 18.5 = 8880 m^3 = 634.2857 d-tons.

Thank you for calling me out on my earlier error and hopefully I have taken the curves into account.